Lines Matching +full:int +full:- +full:map +full:- +full:mask
8 of the API (and actual examples), see Documentation/core-api/dma-api-howto.rst.
11 Part II describes extensions for supporting non-consistent memory
13 non-consistent platforms (this is usually only legacy platforms) you
16 Part I - dma_API
17 ----------------
19 To get the dma_API, you must #include <linux/dma-mapping.h>. This
27 Part Ia - Using large DMA-coherent buffers
28 ------------------------------------------
76 Part Ib - Using small DMA-coherent buffers
77 ------------------------------------------
81 Many drivers need lots of small DMA-coherent memory regions for DMA
84 much like a struct kmem_cache, except that they use the DMA-coherent allocator,
86 for alignment, like queue heads needing to be aligned on N-byte boundaries.
95 dma_pool_create() initializes a pool of DMA-coherent buffers
150 Part Ic - DMA addressing limitations
151 ------------------------------------
155 int
156 dma_set_mask_and_coherent(struct device *dev, u64 mask)
158 Checks to see if the mask is possible and updates the device
159 streaming and coherent DMA mask parameters if it is.
165 int
166 dma_set_mask(struct device *dev, u64 mask)
168 Checks to see if the mask is possible and updates the device
175 int
176 dma_set_coherent_mask(struct device *dev, u64 mask)
178 Checks to see if the mask is possible and updates the device
188 This API returns the mask that the platform requires to
189 operate efficiently. Usually this means the returned mask
191 required mask gives drivers with variable descriptor sizes the
194 Requesting the required mask does not alter the current mask. If you
196 call to set the mask to the value returned.
215 addition, for high-rate short-lived streaming mappings, the upfront time
237 Part Id - Streaming DMA mappings
238 --------------------------------
265 capability, it will fail if the user tries to map a non-physically
271 dma_mask of the device (the dma_mask is a bit mask of the
276 the driver may specify various platform-dependent flags to restrict
297 only map virtual regions that begin and end on page boundaries (which
303 primitive should be treated as read-only by the device. If the device
309 be treated as read-only by the driver. If the driver needs to write
360 used to map device MMIO resources, mapping of RAM is not permitted.
364 int
369 the returned DMA address with dma_mapping_error(). A non-zero return value
375 int
377 int nents, enum dma_data_direction direction)
395 int i, count = dma_map_sg(dev, sglist, nents, direction);
412 accessed sg->address and sg->length as shown above.
418 int nents, enum dma_data_direction direction)
441 int nents,
446 int nents,
460 - Before reading values that have been written by DMA from the device
462 - After writing values that will be written to the device using DMA
464 - before *and* after handing memory to the device if the memory is
481 int
483 int nents, enum dma_data_direction dir,
488 int nents, enum dma_data_direction dir,
495 The interpretation of DMA attributes is architecture-specific, and
497 Documentation/core-api/dma-attributes.rst.
508 #include <linux/dma-mapping.h>
509 /* DMA_ATTR_FOO should be defined in linux/dma-mapping.h and
510 * documented in Documentation/core-api/dma-attributes.rst */
533 Part Ie - IOVA-based DMA mappings
534 ---------------------------------
555 Can be used by the driver to check if the IOVA-based API is used after a
560 int dma_iova_link(struct device *dev, struct dma_iova_state *state,
572 int dma_iova_sync(struct device *dev, struct dma_iova_state *state,
575 Must be called to sync the IOMMU page tables for IOVA-range mapped by one or
578 For drivers that use a one-shot mapping, all ranges can be unmapped and the
605 Part II - Non-coherent DMA allocations
606 --------------------------------------
621 This routine allocates a region of <size> bytes of non-coherent memory. It
654 int
658 Map an allocation returned from dma_alloc_pages() into a user address space.
690 This routine allocates <size> bytes of non-coherent and possibly non-contiguous
696 indicated by sgt->nents, but it might have multiple CPU side segments as
697 indicated by sgt->orig_nents.
735 Once a non-contiguous allocation is mapped using this function, the
752 int
756 Map an allocation returned from dma_alloc_noncontiguous() into a user address
763 int
778 Part III - Debug drivers use of the DMA-API
779 -------------------------------------------
781 The DMA-API as described above has some constraints. DMA addresses must be
787 To debug drivers and find bugs in the usage of the DMA-API checking code can
790 debugging of DMA-API usage" option in your kernel configuration. Enabling this
798 WARNING: at /data2/repos/linux-2.6-iommu/lib/dma-debug.c:448
801 forcedeth 0000:00:08.0: DMA-API: device driver frees DMA memory with wrong
805 Pid: 0, comm: swapper Tainted: G W 2.6.28-dmatest-09289-g8bb99c0 #1
826 <EOI> <4>---[ end trace f6435a98e2a38c0e ]---
829 of the DMA-API call which caused this warning.
837 The debugfs directory for the DMA-API debugging code is called dma-api/. In
841 dma-api/all_errors This file contains a numeric value. If this
847 dma-api/disabled This read-only file contains the character 'Y'
852 dma-api/dump This read-only file contains current DMA
855 dma-api/error_count This file is read-only and shows the total
858 dma-api/num_errors The number in this file shows how many
864 dma-api/min_free_entries This read-only file can be read to get the
870 dma-api/num_free_entries The current number of free dma_debug_entries
873 dma-api/nr_total_entries The total number of dma_debug_entries in the
876 dma-api/driver_filter You can write a name of a driver into this file
885 'dma_debug=off' as a boot parameter. This will disable DMA-API debugging.
895 out of dma_debug_entries and was unable to allocate more on-demand. 65536
896 entries are preallocated at boot - if this is too low for you boot with
910 dma-debug interface debug_dma_mapping_error() to debug drivers that fail